Currently, the mobile communication technology is developing quickly and becomes more and more mature along with the standardization thereof. A current communication system architecture will be described hereinafter briefly.
(1) Evolved Packet System (EPS) Network Architecture
As shown in FIG. 1, an EPS network architecture comprises such entities as a Home Subscriber Server (HSS), a Serving Gateway (SG), a Serving GPRS (General Packet Radio Service) Support Node (SGSN), a Universal Terrestrial Radio Access Network (UTRAN), an Evolved-UTRAN (E-UTRAN), a Mobile Management Entity (MME), a GSM (Global System for Mobile Communications) EDGE Radio Access Network (GERAN), a Public Data Network (PDN) Gateway and a Policy and Charging Rules Function (PCRF). These entities may communicate with each other via various interfaces. In the architecture as shown in FIG. 1, the MME, as a control plane node in a Long Term Evolution (LTE) system, mainly takes charge of controlling all mobile management processes and session management processes in the network. In other words, the processing of the signaling for the mobile management processes and the control over the signaling for the session management processes may be completed by the MME in the network.
It is found that, the load on the MME is obviously too large for the EPS architecture. In the case of a large number of terminals that have accessed to the network, such a centralized network control management for the EPS architecture may easily lead to single-point failures, i.e., the overload may occur for the MME. At this time, network congestion or collapse may occur.
(2) GPRS Network Architecture
As shown in FIG. 2, for a 3rd-Generation (3G) network, an access network consists of a NodeB, and a Radio network controller (RNC) which is mainly configured to forward control signaling and data between the NodeB and a Core Network.
In the 3G network, the core network may take charge of the control over the mobile management and the session management. The SGSN in FIG. 1 has both a control plane function and a user plane function. The SGSN may take charge of all the mobile management processes (including an Attach process, a Tracking Area Update (TAU) process, a Service Request process, a Paging process, a Handover process, a Detach process, etc.) and all the session management processes (including, e.g., the establishment, maintenance and removal of PDN connection and EPS bearer, and the modification of bearer Quality of Service (QoS), and it is also capable of forwarding the user plane-oriented data.
It is found that, the load on the core network is also too large for the GPRS architecture, and in the case of a large number of users and services, the network congestion or collapse may easily occur.
(3) Software Defined Network (SDN) and Network Function Virtualization Network Architecture
On one hand, as shown in FIG. 3, for the SDN network architecture, network resources may be scheduled by an application layer, to some extent, through programming due to the separation of the control plane from a forwarding plane. However, for the SDN itself, the mobile management process and the session management process are too complex, like that in the centralized network architecture.
On the other hand, as shown in FIG. 4, for the NFV network architecture, network devices may be used universally to some extent due to the virtualization of underlying physical hardware resources, and they may be used to extend the network to some extent due to the orchestration of the network functions, so as to make the network heterogeneity possible. However, it is merely able for the NFV network to cancel the difference among the hardware devices from an Information Technology (IT) perspective, thereby to enable the mobile communication network to be deployed on a general-purpose hardware platform. In other words, problems may still occur for the convergence and collaboration of heterogeneous networks.
In a word, for the EPS, GPRS, SDN and NFV network architectures, in the case of a large number of terminals that have accessed to the network, the above-mentioned centralized control scheme in the traditional mobile communication network is expensive and inefficient. In addition, the network capacity is limited and the signaling overhead is large.
Hence, it is impossible for the current network architecture to effectively deal with such situations where a large number of terminals have accessed the network and a large number of burst services occur, i.e., the current network architecture cannot be adapted to the future network, and no effective scheme have been proposed yet.